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2015-04-17fix PLT call offset in sh dlsym asmRich Felker-3/+3
the braf instruction's destination register is an offset from the address of the braf instruction plus 4 (or equivalently, the address of the next instruction after the delay slot). the code for dlsym was incorrectly computing the offset to pass using the address of the delay slot itself. in other places, a label was placed after the delay slot, but I find this confusing. putting the label on the branch instruction itself, and manually adding 4, makes it more clear which branch the offset in the constant pool goes with.
2015-04-17fix sh build regressions in asmRich Felker-1/+1
even hidden functions need @PLT symbol references; otherwise an absolute address is produced instead of a PC-relative one.
2015-04-14use hidden visibility for call from dlsym to internal __dlsymRich Felker-1/+2
2015-04-13dynamic linker bootstrap overhaulRich Felker-26/+0
this overhaul further reduces the amount of arch-specific code needed by the dynamic linker and removes a number of assumptions, including: - that symbolic function references inside libc are bound at link time via the linker option -Bsymbolic-functions. - that libc functions used by the dynamic linker do not require access to data symbols. - that static/internal function calls and data accesses can be made without performing any relocations, or that arch-specific startup code handled any such relocations needed. removing these assumptions paves the way for allowing libc.so itself to be built with stack protector (among other things), and is achieved by a three-stage bootstrap process: 1. relative relocations are processed with a flat function. 2. symbolic relocations are processed with no external calls/data. 3. main program and dependency libs are processed with a fully-functional libc/ldso. reduction in arch-specific code is achived through the following: - crt_arch.h, used for generating crt1.o, now provides the entry point for the dynamic linker too. - asm is no longer responsible for skipping the beginning of argv[] when ldso is invoked as a command. - the functionality previously provided by __reloc_self for heavily GOT-dependent RISC archs is now the arch-agnostic stage-1. - arch-specific relocation type codes are mapped directly as macros rather than via an inline translation function/switch statement.
2014-06-20rename dynamic linker entry point from _start to _dlstartRich Felker-3/+3
the main motivation for this change is to aid in debugging. since the main program's entry point is also named _start, it was difficult to set breakpoints or quickly identify which _start execution stopped in.
2014-02-27rename superh port to "sh" for consistencyRich Felker-0/+36
linux, gcc, etc. all use "sh" as the name for the superh arch. there was already some inconsistency internally in musl: the dynamic linker was searching for "ld-musl-sh.path" as its path file despite its own name being "ld-musl-superh.so.1". there was some sentiment in both directions as to how to resolve the inconsistency, but overall "sh" was favored.